隨著全球綠能的發展，大型儲能系統的需求也隨之提升，全釩液流電池(Vanadium redox flow battery, VRFB)因其擁有許多優點，而成為受到矚目的大型儲能系統之一，全釩液流電池的電極通常使用具有導電性的石墨材料，然而這些石墨材料往往有著導電性不足、電化學活性差等缺點，這些問題將導致全釩液流電池的效能不佳。因此，本研究將作為電極的石墨氈改質，藉由奈米線的鈦酸鋰與二氧化鈦複合物三維修飾石墨氈，直接將觸媒合成於石墨氈纖維的表面，藉此減少觸媒與石墨氈之間的電阻，並藉由三維的奈米線形貌，提升電極與電解液之間的反應面積，進而達到提升全釩液流電池效能的目的。
為了進一步證明鈦酸鋰與二氧化鈦的複合物修飾的石墨氈的效果，將修飾後的石墨氈電極應用於全釩液流電池的正與負極，並進行不同電流密度的充、放電測試，對於伏特效率而言，經過觸媒修飾的石墨氈電極明顯具有更好的結果，當電流密度提升為200 mA/cm2時，其能量效率可達60.57%，比熱處理石墨氈高出8.63%，且放電電容量也提升5.123倍。在電流密度160 mA/cm2的穩定性測試中，將全釩液流電池進行60次的循環充、放電，整體的效能並沒有明顯的變化，這象徵著經由鈦酸鋰與二氧化鈦複合物所改質的石墨氈電極，不僅僅可以有效提升全釩液流電池的效能，其還展現出可以長時間使用的穩定性。

With the development of global green energy, the demand for large-scale energy storage systems has also increased. Vanadium redox flow battery (VRFB) is one of the large-scale energy storage systems, has attracted attention because of its several merits. However, the graphite electrode materials employed for VRFB often have shortcomings such as insufficient conductivity and poor electrochemical activity, leading to poor performance of VRFB. To modify the graphite felt electrode, in this study, lithium titanate/titanium dioxide (LTO/TiO2) composite catalyst with the nanowire morphology was directly grown on the surface of the graphite felt fiber. The conductivity of the graphite felt electrode through the 3D nanowire morphology, the reaction area between the electrode and the electrolyte is increased, thereby improving the performance of VRFB.
In order to further prove the effect of the graphite felt modified by the composite material of LTO/TiO2, the modified graphite felt electrode was applied to the positive and negative electrodes of VRFB, and the charge and discharge tests at different current densities were carried out. In terms of efficiency, the catalyst-modified graphite felt electrode has obviously better results. When the current density is increased to 200 mA/cm2, its energy efficiency can reach 60.57%, which is 8.63% higher than that of the heat-treated graphite felt. In the stability test with a current density of 160 mA/cm2, the VRFB was charged and discharged for 60 cycles, and the overall performance did not change significantly, which means that the composite material of lithium titanate and titanium dioxide not only effectively improve the performance of the VRFB, but also show the stability that can be used for a long time.

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